Create 20240326_04.md

Author: digoal

202403/20240326_04.md

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+## PostgreSQL 17 preview - 支持修改分区表access method     
+                                                                                    
+### 作者                                                                                    
+digoal                                                                                    
+                                                                                    
+### 日期                                                                                    
+2024-03-26                                                                             
+                                                                                    
+### 标签                                                                                    
+PostgreSQL , PolarDB , DuckDB , 分区表 , access method                       
+                                                                                    
+----                                                                                    
+                                                                                    
+## 背景        
+    
+https://git.postgresql.org/gitweb/?p=postgresql.git;a=commit;h=374c7a2290429eac3217b0c7b0b485db9c2bcc72    
+```    
+Allow specifying an access method for partitioned tables  
+  
+author	Alvaro Herrera <[email protected]>	  
+Mon, 25 Mar 2024 15:30:36 +0000 (16:30 +0100)  
+committer	Alvaro Herrera <[email protected]>	  
+Mon, 25 Mar 2024 15:30:36 +0000 (16:30 +0100)  
+commit	374c7a2290429eac3217b0c7b0b485db9c2bcc72  
+tree	569f900a12d9a95d881f2dc45faf6ad285decdd9	tree  
+parent	b8528fe026b18976b5d5b4fcb066a8a55def3375	commit | diff  
+Allow specifying an access method for partitioned tables  
+  
+It's now possible to specify a table access method via  
+CREATE TABLE ... USING for a partitioned table, as well change it with  
+ALTER TABLE ... SET ACCESS METHOD.  Specifying an AM for a partitioned  
+table lets the value be used for all future partitions created under it,  
+closely mirroring the behavior of the TABLESPACE option for partitioned  
+tables.  Existing partitions are not modified.  
+  
+For a partitioned table with no AM specified, any new partitions are  
+created with the default_table_access_method.  
+  
+Also add ALTER TABLE ... SET ACCESS METHOD DEFAULT, which reverts to the  
+original state of using the default for new partitions.  
+  
+The relcache of partitioned tables is not changed: rd_tableam is not  
+set, even if a partitioned table has a relam set.  
+  
+Author: Justin Pryzby <[email protected]>  
+Author: Soumyadeep Chakraborty <[email protected]>  
+Author: Michaël Paquier <[email protected]>  
+Reviewed-by: The authors themselves  
+Discussion: https://postgr.es/m/CAE-ML+9zM4wJCGCBGv01k96qQ3gFv4WFcFy=zqPHKeaEFwwv6A@mail.gmail.com  
+Discussion: https://postgr.es/m/20210308010707.GA29832%40telsasoft.com  
+```    
+     
+    
+